Inhibition of color formation during sulfation of ethoxylated alcohols and alkyl phenols

ABSTRACT

Light-colored sulfates of ethoxylated long chain aliphatic alcohols and of ethoxylated alkylphenols are produced by carrying out the sulfation, using sulfur trioxide dissolved in liquid sulfur dioxide as the sulfating agent, in the presence of small amount of a borohydride such as sodium borohydride.

United States Patent Kapur et al. 1 Aug. 29, 197 2 [54] INHIBITION OF COLOR FORMATION [56] References Cited DURING SULFATION OF I UNITED STATES PATENTS ETHOXYLATED ALCOHOLS AND 3 150 161 9/1964 N 260/458 unn 2,928,860 3/1960 Havington ..260/458 Inventors: u J- Kap 325 18th 3,376,333 4/1968 Ernst et a1. ..260/458 Paterson, NJ. 07524; Marvin L. Mausner, 531 Cumberland Ave., imary Ex miner-Leon Zitver Teaneck, NJ, 07666 Assistant Examiner-Leo B. DeCrescente Attorne Wallenstein, S an enber Hattis and 22 Flledz Nov. 14, 1969 swamp; p g g [21] Appl.No.: 877,016

[ ABSTRACT Light-colored sulfates of ethoxylated long chain [52] US. Cl ..260/458 aliphatic alcohols and of ethoxylated alkylphenols are [51] Int. Cl ..C07c 141/02. produced by carrying out the Sulfation, using sulfur trioxide dissolved in liquid sulfur dioxide as the sulfatlTeld of Search ..260/458 ing agent, in the presence of small amount of a borohydride such as sodium borohydride.

3 Claims, No Drawings INHEITION OF COLOR FORMATION DURING SULFATION F ETHOXYLATED ALCOHOLS AND ALKYL PHENOLS Our invention is directed to improvements in the production of sulfated ethoxylated long chain aliphatic alcohols and sulfated ethoxylated alkylphenols specifically in regard to the production of light colored sulfated products, by inhibiting the formation of colored bodies through the inclusion, during the sulfation reaction, of color inhibiting amounts of certain compounds described in detail below.

It is well known that, in the sulfation of ethoxylated long chain aliphatic alcohols and of ethoxylated alkylphenols, colored byproduct bodies are formed which are objectionable since it is a desirable attribute of the finished sulfated products that they possess a light color. Various approaches have, accordingly, been suggested to overcome such objections as, for instance, the carrying out of the sulfation reaction in the presence of such agents as hypophosphorous acid and salts, as is disclosed in British Pat. No. 903,204. Other procedures which have been suggested, in relation to eliminating objectionable color from sulfated products such as sulfated long chain alcohols, have been to effect bleaching of the sulfated long chain alcohols after the completion of the sulfation reaction, as shown, for instance, in U.S. Pat. No. 2,846,457; and by carrying out of the sulfation reaction in the presence of thioamides such as thiourea and thioacetamide, as shown in US. Pat. No. 2,928,860.

We have discovered that, by carrying out the sulfation of the ethoxylated-long chain aliphatic alcohols or the ethoxylated alkylphenols in the presence of a small or minor amount of a borohydride, the resulting sulfated products possess a highly desirable light color. The color bodies the inhibition of formation of which is achieved by the practice of our invention are those which result from carrying out the sulfonations with sulfur trioxide dissolved in liquid sulfur dioxide.

Various borohydrides can be employed in the practice of our invention, namely, alkali metal borohydrides, alkaline earth metal borohydrides and quaternary alkyl ammonium borohydrides wherein the alkyl moieties contain, for instance, from one to four carbon atoms, illustrative examples of which are the borohydrides of sodium, potassium, lithium, calcium, barium, magnesium, strontium and lithium-aluminum; tetramethylammonium borohydride, tetraethylammonium borohydride, tetrapropylammonium borohydride, tetraisopropylammonium borohydride, and tetrabutylammonium borohydrides. Particularly satisfactory is sodium borohydride. The borohydrides are utilized in quite small proportions, generally of the order of 0.01 to 0.2 percent based upon the weight of the sulfated ethoxylated alkylphenol, particularly satisfactory in most cases being about 0.05 to 0.1 percent.

The ethoxylated long chain aliphatic alcohols and ethoxylated alkylphenols which are sulfated in accordance with our invention, in the presence of a color inhibiting amount of a borohydride, are conveniently made by adducting a long chain, C to C aliphatic alcohol or C to C alkylphenol with ethylene oxide. The number of moles of ethylene oxide per mole of long chain aliphatic alcohol or alkylphenol is variable within wide limits but, in general, there is at least 1 mole and there may be up to 30 or more moles of ethylene oxide per mole of the long chain aliphatic alcohol or alkylphenol, preferably from 4 to 20 and particularly from 6 to 15 moles of the ethylene oxide per mole of the long chain aliphatic alcohol or alkylphenol.

The long chain aliphatic alcohols and the alkylphenols the ethylene oxide adducts of which are sulfated in accordance with our present invention include, by way of illustration, aliphatic (including cycloaliphatic) straight chain and branched chain alcohols, such as octyl alcohol, decyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, oleyl alcohol, palmitoleyl alcohol, stearyl alcohol; oxo alcohols such as the primary monohydric saturated aliphatic alcohols of about 10 to 20 carbon atoms produced by the 0X0 process as, for instance, oxo tridecyl alcohol and oxo hexadecyl alcohol (see US. Pat. No. 2,965,678 for a more detailed disclosure of such oxo alcohols); alkylphenols, including monoand di-alkylphenols in which the alkyl radicals contain from five to 15 carbon atoms, exemplified by amylphenol, diamylphenol, hexylphenol, dihexylphenol, octylphenol, dioctylphenol, and monoand di-nonyl, decyl, undecyl, dodecyl and tridecyl phenols.

The ethylene oxide may be replaced, in part, by propylene oxide and/or butylene oxide, generally up to about 25 percent by weight of the total of the alkylene oxides present in the molecules of the adducts and, in the making of said adducts, mixtures of the ethylene oxide and propylene and/or butylene oxides can be used, or, alternatively, the adduction of the long chain aliphatic alcohol or alkylphenol may first be effected with the ethylene oxide, followed by the propylene and/or butylene oxide; or the adduction with the propylene oxide and/or butylene oxide may be effected followed by the adduction with the ethylene oxide. For best results, however, the straight ethylene oxide adducts are utilized without any propylene oxide or butylene oxide.

Illustrative examples of the ethoxylated long chain aliphatic alcohols and ethoxylated alkylphenols which can be sulfated in accordance with the present invention to obtain highly desirable light colored sulfated products are the following, the letters E.O. standing for ethylene oxide, the letters P.O. standing for propylene oxide and the number precedingthe same standing for the number of moles thereof adducted or reacted with 1 mole of the stated alcohol or alkyl phenol.

n-octyl alcohol 4 E.O. iso-octyl alcohol 3 E.O. lauryl alcohol 10 E.O. myristyl alcohol 11 E.O. hexadecyl alcohol 15 E.O. octadecyl alcohol 18 E.O. oleyl alcohol 17 E.O. Oxo tridecyl alcohol 8 E.O. Oxo pentadecyl alcohol 12 E.O. diamylphenol 4 E.O. nonylphenol 8 E.O. dinonylphenol 10 E.O. dodecylphenol 7 E.O. tridecylphenol 9 E.O. lauryl alcohol 4 E.O. & 1 P0. hexadecyl alcohol 10 E.O. 2 PD. nonylphenol 7 E.O. l P.O.

Other ethoxylated long chain aliphatic alcohols and ethoxylated alkylphenols which can be sulfated in accordance with our invention are disclosed in numerous patents, illustrative of which is the aforementioned British Pat. No. 903,204.

No novelty is claimed in the sulfation procedure per se which is utilized in the production of the sulfated ethoxylated long chain aliphatic alcohols or ethoxylated alkylphenols. Sulfur trioxide dissolved in sulfur dioxide is a well known sulfating system and is disclosed in numerous patents and other printed publications, illustrative of said US. Patents being Nos. 2,928,867 and 2,831,020. In those cases in which the ethoxylated long chain aliphatic alcohol or ethoxylated alkylphenol is a solid at room temperature, it should be heated to above its melting point before the sulfating agent is added thereto. The sulfation is carried out under vigorous stirring or agitation and under substantially anhydrous conditions, preferably under controlled temperature and utilizing an excess of the sulfating agent. Generally speaking, it is advantageous to carry out the sulfation at temperatures in the range of to -20C. After completion of the sulfation reaction, the sulfated products can be neutralized in well known ways to form, for instance, the sodium, potassium, am-

monium, calcium, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethylamine, isopropylamine, cyclohexylamine,

dicyclohexylamine or other amine or other salts.

We are aware of the fact that borohydrides have heretofore been suggested for use in certain reactions to produce improved color in the resulting reaction products, as, for instance, in the purification of crude phthalic anhydride (US. Pat. No. 3,328,429). This type of chemical reaction bears no relationship to the considerations which apply to inhibiting objectionable color formation in the sulfation of ethoxylated long chain aliphatic alcohols and ethoxylated alkylphenols.

The following examples are illustrative of the practice of our invention and are not to be construed as in any way limitative thereof since various changes can be made in the light of the guiding principles and teachings disclosed herein.

EXAMPLE 1 To 166 grams of a 3mol ethylene oxide adduct of a mixture of C and C linear aliphatic alcohols was added 0.83 grams of NaBH Then 166 grams of liquid S0 at 5C was added. The mixture was stirred for 1 hour until all the alcohol dissolved in the S0 Next was added a mixture of 43 grams S0 and 380 grams S0 Throughout the addition of the SO SO the color of the sulfate ester formed remained colorless. After stripping of S0 the sulfate ester was a light yellow color. On neutralization the Klett color of the finished product was 123.

EXAMPLE 2 Example 1 was repeated, except that only 0.166 grams of NaBI-L (0.1 percent by weight) was added to the alcohol. On addition of $0 -$0 the color of the sulfate ester remained colorless except during the addition of the final 25 percent of $0 -$0 the sulfate turned a light brown. On stripping of S0 the color was a transparent brown. Neutralization gave a Klett color of 475 which after 3 dais reduced to 220.

E AMPLE 3 Example 1 was repeated except that no NaBl-I, was added. Immediately upon addition of SO,SO the mixture darkened in color. The color before and after stripping of S0 was dark brown. On neutralization, the Klett color of the finished product was 950 and in 2 days had only dropped to 650.

EXAMPLE 4 The process of example 1 is carried out except that 0.5 mol of a 5 mol ethylene oxide adduct of nonylphenol is used with 425 grams of the sulfating solution. A light colored sulfated ethoxylated nonylphenol is obtained.

EXAMPLE 5 The process of example 1 is carried out except that 0.75 grams of lithium borohydride is used in place of the sodium borohydride. A light colored sulfated ethoxylated alcohol is obtained.

EXAMPLE 6 The process of example 2 is carried out except that 0.80 grams of tetramethylammonium borohydride is used in place of the sodium borohydride. A light colored sulfated ethoxylated alcohol is obtained.

We claim:

1. In that method of producing sulfated ethoxylated C to C aliphatic alcohols and sulfated ethoxylated C to C monoand dialkyl phenols, wherein the sulfation is effected by means of sulfur trioxide dissolved in liquid sulfur dioxide, the improvement which comprises carrying out said sulfation reaction in the presence of a color inhibiting amount of a borohydride selected from the group consisting of alkali metal borohydrides, alkaline earth metal borohydrides and quaternary alkyl ammonium borohydrides, wherein the alkyl moieties contain from one to four carbon atoms.

2. The method of claim 1 in which the borohydride is sodium borohydride.

3. The method of claim 1 in which the borohydride is sodium borohydride and which is present in proportions of from about 0.01 to 0.2 percent based upon the weight of the sulfated ethoxylated product produced.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,687 999 Dated Ag gugt Z2 1Q Z2 Inventor(s) Brij L. Kapur, et. a1.

It is certified that error appears in the above-identified patent. and that said Letters Patent are hereby corrected as shown below:

On the cover sheet, insert-"r?- [731- Assignors To Witco Chemical Corporation, New York, N.Y. a Corporation of Delaware.

Signed and sealed this 20th day of March 1973.

(SEAL) 1s Attest:

EDWARD M. FLETCHER, JR. ROBERT coT'rscHAfiK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMM-DC 6O376-F69 U.5. GOVERNMENT PRINTING OFFICE: 1969 0-366-33L 

2. The method of claim 1 in which the borohydride is sodium borohydride.
 3. The method of claim 1 in which the borohydride is sodium borohydride and which is present in proportions of from about 0.01 to 0.2 percent based upon the weight of the sulfated ethoxylated product produced. 